Evolution, ecology and genomics of the Great Lakes invader, the red algal species Bangia atropurpurea.

五大湖入侵者红藻物种 Bangia atropurpurea 的进化、生态学和基因组学。

• 批准号: RGPIN-2018-03977
• 负责人: Muller, Kirsten
• 金额: $ 2.04万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=711189
• 关键词: Evolution; ecology; genomics; Great; Lakes

The red algae (Rhodophyta) are an ancient lineage in the fossil record dating 1.2 and 1.7 Ga; both of these fossils have pushed back the evolution of multicellularity in eukaryotes and the evolution of sexual reproduction. Furthermore, the red algae are a critical group in the evolution of photosynthetic life on earth containing primary chloroplasts and have also contributed chloroplasts through secondary and tertiary endosymbiosis to other eukaryotic lineages. Despite the obvious importance of this group, little is still known about many red algal lineages, in particular, the more basal classes within the phylum. Only recently, has genomic sequencing been used to examine members of this phylum and have noted differences among the red algae and other eukaryotes, as well as unique stress tolerances. In this proposal, we aim to sequence the genome and selected transcriptomes of the species Bangia atropurpurea. This research proposal would be the first to sequence the genome of a strictly freshwater red algal species, and this species is also an invader in the Laurentian Great Lakes. It is important to note that Bangia is the only genus in the red algae to have a species solely in freshwater (not brackish) and others in the marine environment and it is the only red alga to have been shown to experimentally transition from marine to freshwater or vice versa. Hence, this genus is an excellent model organism to examine transcriptomic changes due to osmotic stress and we will be able to identify genes that are involved in the process of acclimation and osmotic stress and predict the limits that control invasion into new habitats. In addition, the 1.2 Ga red algal fossil is morphologically indistinguishable from Bangia and hence is the oldest taxonomically resolved eukaryote fossil. This fossil provided the first evidence for sexual reproduction in the fossil record for eukaryotes and as a result, this genus is ideal to study the evolution of sexual reproduction as well as the expression of genes in different stages of the life history. Bangia atropurpurea is known to only reproduce asexually, and this particulary mode of reproduction enables it to be an effective invader into new habitats.

红藻（Rhodophyta）是化石记录中的古老谱系，日期为1.2和1.7 GA；这两种化石都推迟了真核生物中多细胞的演变和有性繁殖的演变。此外，红藻是地球上含有原发性叶绿体的光合作用演变的关键群体，还通过继发性和第三级内共生生物造成叶绿体对其他真核生物谱系的贡献。尽管这一组显而易见，但对于许多红色藻类谱系，尤其是门内较大的基础类别仍然知之甚少。直到最近，基因组测序才用于检查该门的成员，并注意到红藻和其他真核生物之间的差异以及独特的胁迫耐受性。在此提案中，我们旨在对班尼亚阿托罗普利亚物种的基因组和选定的转录组进行测序。这项研究建议将是第一个对严格淡水红色藻类物种的基因组进行测序的，该物种也是劳伦斯大湖区的入侵者。 重要的是要注意，Bangia是红藻中唯一仅在淡水中拥有一个物种（而非咸味）和其他在海洋环境中的物种的属，并且它是唯一证明从实验中从海洋上过渡到淡水或反之亦然的红色藻类。 因此，该属是一种出色的模型生物体，可以检查由于渗透压而引起的转录组变化，我们将能够鉴定出与适应和渗透压过程有关的基因，并预测控制入侵新栖息地的限制。此外，1.2 GA红色藻类化石在形态上与班加亚无法区分，因此是最古老的分类学分类真核化石。 这种化石为真核生物的化石记录提供了有性繁殖的第一个证据，因此，该属是研究有性繁殖演变以及基因在生活史的不同阶段的表达的理想选择。已知Bangia Atropurpurea仅无性繁殖，而这种特别的繁殖模式使其可以有效地入侵新栖息地。